This little gem of a book introduces the key aspects of mobile technology affecting human-computer interaction, which could dramatically transform our day-to-day lives. It also provides general guidance on research methods, including data analysis, and plenty of external references. This book could serve as a supplemental text for an undergraduate class in psychology, information systems, or the social sciences. Steve Love conveys the mobile technology's strong impact on HCI by presenting issues from three main disciplines—cognitive psychology, application design, and the social sciences—and he uses cell phones and PDAs as his main example devices. The book doesn't cover computer science issues or mobile HCI theory in great detail but discusses issues pertinent to research projects.

I was interested in reading this book to learn about human-in-the-loop issues in a multiagent system composed of humans and nonhuman autonomous agents. Mobile devices, although not entirely autonomous, are smart devices connecting humans in a multiagent system. Those devices mediate interaction with other agents and will therefore be a key issue in future HCI research. The topics the book covered were thought-provoking and conducive to research.

Room for organizational improvement

In addition to mobile HCI-specific issues, the book includes a chapter on HCI research methods and general chapters on research methods, research guidelines, and data analysis. The chapter order is somewhat confusing. The chapters on general and HCI research methods understandably come after the chapter about the psychology perspective because these methods are designed with the single user in mind. However, usability testing, as presented in the application design chapter, also has the single user in mind. Research guidelines and data analysis chapters follow the chapter that considers the social sciences perspective. This confusion only stresses mobile HCI's novelty and the fact that a combined research methodology hasn't been developed yet.

A multidisciplinary approach

From the psychology viewpoint, user characteristics issues include spatial orientation, personality, memory, age, and verbal ability. Mental models, such as mental navigation, must translate into physical constraints to produce a usable interface. Outside of peoples' ability differences, it's not obvious why one interface will work better for one set of users than another.

The book does well in debunking some myths about user personality and in explaining how users' perception—the projection of a personality onto the computer—causes differences in usability. User characteristics affect how users perceive computers, and this perception is a key HCI issue. Adjusting interactions to the user characteristics to project a favorable perception is an interesting avenue of research. The issue of individual differences versus universal access is also particularly acute for mobile devices because they are personal devices. One way researchers and designers have addressed this issue is by providing personalization capabilities.

From an application design viewpoint, HCI issues become usability and user-centered design issues. The key issue here is context of use, which considers the user's social context. Context awareness is especially important in mobile technology because the environment can be arbitrarily diverse. Context-of-use further constrains the type of interaction (for example, speech-based or keypad-based) that would be most usable. This part of the book lightly covers computer science issues such as speech recognition and dialogue management because they affect usability.

Short-term memory constraints affect the complexity of information that mobile devices can present. In this context, using metaphors such as "shopping cart" and "desktop" is a great technique for developing usable interfaces; by relating to something familiar, developers can convey more information with less complexity. The jury is still out on what metaphors to use for mobile devices, but the book provides some ideas and references.

The application design chapter also provides specific research methods for user-centered design such as Wizard-of-Oz prototyping. It points to a phone emulator, Openwave, to test mobile applications. A computer science student would be interested here in the protocols used to transmit information between users.

Love presents the social sciences perspective from the social usability viewpoint. Social usability is roughly defined as environmental and social factors (that is, norms and conventions) influencing the use of mobile technology. "Civil inattentiveness" is a specific issue of mobile technology's obtrusiveness with respect to social usability that happens when social norms are violated. For example, drawing people involuntarily into personal mobile phone conversations is a common problem. The book does a good job of presenting this issue as potentially altering current behavioral patterns.

Another set of issues this chapter introduces is that of "mobile workers," such as healthcare providers. This relatively new class of workers is characterized by their dependency on mobile technology to stay in touch with team members and their need to switch between different contexts of use.

Communication technology issues, such as reliability, bandwidth, latencies, and privacy, aren't included here, but the book concludes by discussing the promise of increased bandwidth that will further increase mobile technology's impact on our day-to-day lives. Love also summarizes future areas of mobile HCI research that he introduced throughout the book: location-based services, research methods, collaborative learning, healthcare, and personalization.

Project exercises and a self-test glossary of key concepts follow each chapter. This book has several typos that should be caught in a second printing, but they're not too distracting.

Understanding Mobile Human-Computer Interaction is a great introduction and fits well in the undergraduate curriculum. I found the inclusion of chapters on research methods, research guidelines, and data analysis somewhat surprising, because these topics could be covered elsewhere. They're quite good and concise, however, and make the book self-contained as a field guide to mobile HCI. I would recommend the book to get anybody acquainted with HCI in general. Love presents difficult concepts particularly well, and the book is enjoyable.

Myriam Abramson is a computer scientist at the US Naval Research Laboratory. Contact her at myriam.abramson@nrl.navy.mil.